Strength of schedule
LSU has two big wins
What? Not number one?
When Wisconsin’s 31 point win over Nebraska moved them to second in The Power Rank last week, Brian Hammer shared a link on Facebook. Brian is engaged to Val, a very close friend who was the maid of honor at our wedding. They live in Madison and have gotten swept up in Badger fever this fall. Brian’s friend Parker Anderson saw the link and commented, “I’m having trouble wrapping my head around an algorithm that rewards wins over ranked opponents and doesn’t put LSU #1.” Now, Parker clearly cares about college football, as his profile picture shows him with ESPN’s Kirk Herbstreit, presumably from when College Game Day visited Madison last week. Moreover, he must have clicked on the “About” page of this site to get an idea about our analytic methods. Teams earn their rank by beating other highly ranked teams. So how do we explain why LSU, who has beaten Oregon (7) by 13 and West Virginia (23) by 26, lingers at 4th in our rankings, behind Alabama, Stanford and Boise State?
Good question. In our early season rankings, we use a one year window of games, with this year’s games counted twice. For LSU, this set of games includes last year’s loss to Auburn and every game since then. Of course, we could also use only games from this year, which gives us different rankings.
1. Alabama, 6-0, 34.20
2. LSU, 6-0, 31.35
3. Wisconsin, 5-0, 31.17
4. Stanford, 5-0, 27.58
5. Boise State, 5-0, 25.37
6. Oklahoma, 5-0, 24.03
7. Oregon, 4-1, 23.89
8. Oklahoma State, 5-0, 22.21
9. Michigan, 6-0, 18.34
10. Texas A&M, 3-2, 16.88
11. Arkansas, 5-1, 16.05
12. Clemson, 6-0, 14.04
13. Notre Dame, 4-2, 13.81
14. Arizona State, 5-1, 13.10
15. Rutgers, 4-1, 12.93
16. Penn State, 5-1, 12.79
17. Georgia, 4-2, 11.42
18. Missouri, 2-3, 10.80
19. Baylor, 4-1, 9.78
20. Florida State, 2-3, 9.58
Since these rankings reflect what teams have earned on the field this year, they more closely correspond conventional wisdom and the AP poll. However, LSU still comes in 2nd behind Alabama. The algorithm thinks more highly of Alabama’s 24 point home win over Arkansas (9) than LSU’s 13 point win in Dallas over Oregon (7), the toughest games played by either team this year. In the AP poll, Alabama didn’t get the credit they deserved for this Arkansas win because LSU went on the road to beat West Virginia that same week.
The rankings with games from last year make better predictions, and these predictions are more important than evaluating teams on their play this year. In this year’s college football games, the rankings that use a one window of games predicts the correct winner in 73.6% of 638 games played between two Division I teams. The rankings that only use games from this year can only make predictions after week 4 and predict winners in 69.1% of 217 games. While football will always have a limited number of games, the algorithm can contemplate 82 regular season games per team in the NBA. With all this data, it predicts the winner in 70.0% of 2330 late season games over the last 4 years. For comparison, the line picked 70.8% winners in this same set of games.
Also, we can already see how more games tends to depress the ratings of top teams like Alabama and LSU. For example, LSU has a 31.4 rating using only this year’s games but a 24.2 rating in the actual rankings. LSU enjoyed a 4-1 and 4-0 turnover edge against Oregon and West Virginia, respectively, which padded the margin of victory in both games. LSU cornerback Tyrann Mathieu forced a fumble and scored a touchdown against Oregon, but we don’t consider this lucky as our Heisman frontrunner continues to create turnovers in other games. However, LSU benefitted from 2 fumbles by Oregon true freshman De’Anthony Thomas in his first college game, a performance unlikely to be repeated if Oregon played LSU again. Considering more games in our rankings averages out this luck.
Of course, there are problems with using games from last year. Auburn shows up at 10th in the rankings based on their incredible late season performance last year. However, quarterback Cam Newton and defensive tackle Nick Fairley are gone, casting doubt on this high ranking. Their 38th ranking in our results using only games this year is probably a more accurate assessment. Ohio State still lingers at 18th on the strength of last year’s games. Without coach Jim Tressel this year, Ohio State is painful to watch and comes in 53rd in our rankings with only this year’s games.
So thanks, Parker, for caring enough about college football to make a stink about LSU. And while we’re addressing the concerns of fans from Madison, we should explain why Wisconsin dropped to 5th without playing a game. Stanford (+41 over Colorado), Boise State (+50 on the road at Fresno State) and LSU (+30 against Florida) all scored huge wins over the weekend that boosted their ratings significantly. Still, all four of these teams remain within 1.3 points of each other. Let’s play some more football.